Synchronizing a 5g communication channel using a 4g timing synchronization parameter

ABSTRACT

A method for clock synchronization in a communication system having first circuitry coupled to a first communication channel and second circuitry, includes generating a first timing synchronization parameter, and synchronizing the second circuitry to a second communication channel using the first timing synchronization parameter.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/592,260, entitled “Synchronizing A 5G Communication Channel Using A4G Timing Synchronization Parameter,” filed on May 11, 2017, whichclaims the benefit of U.S. Provisional Patent Application No.62/398,186, entitled “Synchronizing 5G Communication Channel Using 4GSynchronization Parameter,” filed Sep. 22, 2016, the contents of bothapplications being hereby incorporated by reference in their entirety.

FIELD

The present disclosure relates to wireless communication systems, andmore particularly to timing synchronization in wireless communications.

BACKGROUND

Wireless communication systems are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be multiple-accesssystems capable of supporting communication with multiple users bysharing the available system resources (e.g., time, frequency, andpower). Examples of such multiple-access systems include code-divisionmultiple access (CDMA) systems, time-division multiple access (TDMA)systems, frequency-division multiple access (FDMA) systems, andorthogonal frequency-division multiple access (OFDMA) systems.

By way of example, a wireless multiple-access communication system mayinclude a number of base stations, each simultaneously supportingcommunication for multiple communication devices, otherwise known asuser equipments (UEs). A base station may communicate with UEs ondownlink channels (e.g., for transmissions from a base station to a UE)and uplink channels (e.g., for transmissions from a UE to a basestation). UEs may locate a base station by detecting synchronizationsignal(s) from which the UEs acquire the base station identificationcode (cell ID), system timing information, frame alignment information,etc. In systems where the receiver is highly signal strength and noiselimited (e.g., millimeter wave systems), beamformed synchronizationsignals may be swept across the cell coverage area to provide coverageenhancement to improve detection.

SUMMARY

Various implementations of systems, methods and devices within the scopeof the appended claims each have several aspects, no single one of whichis solely responsible for the desirable attributes described herein.Without limiting the scope of the appended claims, some prominentfeatures are described herein.

Details of one or more implementations of the subject matter describedin this specification are set forth in the accompanying drawings and thedescription below. Other features, aspects, and advantages will becomeapparent from the description, the drawings, and the claims. Note thatthe relative dimensions of the following figures may not be drawn toscale.

One aspect of the disclosure provides a method for clock synchronizationin a communication system having first circuitry coupled to a firstcommunication channel and second circuitry, the method includinggenerating a first timing synchronization parameter, and synchronizingthe second circuitry to a second communication channel using the firsttiming synchronization parameter.

Another aspect of the disclosure provides an apparatus for clocksynchronization in a communication system including first circuitrycoupled to a first communication channel, second circuitry, and a firsttiming synchronization parameter configured to allow the secondcircuitry to establish communication with a second communicationchannel.

Another aspect of the disclosure provides a device including means forcoupling first circuitry to a first communication channel, means forgenerating a first timing synchronization parameter, and means forsynchronizing second circuitry to a second communication channel usingthe first timing synchronization parameter.

Another aspect of the disclosure provides a non-transitorycomputer-readable medium storing computer executable code for clocksynchronization in a communication system having first circuitry coupledto a first communication channel and second circuitry, the codeexecutable by a processor to generate a first timing synchronizationparameter, and synchronize the second circuitry to a secondcommunication channel using the first timing synchronization parameter.

BRIEF DESCRIPTION OF THE DRAWINGS

In the figures, like reference numerals refer to like parts throughoutthe various views unless otherwise indicated. For reference numeralswith letter character designations such as “102 a” or “102 b”, theletter character designations may differentiate two like parts orelements present in the same figure. Letter character designations forreference numerals may be omitted when it is intended that a referencenumeral encompass all parts having the same reference numeral in allfigures.

FIG. 1 is a diagram showing a wireless communication system, inaccordance with various aspects of the present disclosure.

FIG. 2 is a block diagram showing a device configured for use inwireless communication, in accordance with various aspects of thepresent disclosure.

FIG. 3 is a block diagram showing a device configured for use inwireless communication, in accordance with various aspects of thepresent disclosure.

FIG. 4 is a block diagram showing a device configured for use inwireless communication, in accordance with various aspects of thepresent disclosure.

FIG. 5 is a block diagram showing a wireless communication system, inaccordance with various aspects of the present disclosure.

FIG. 6 is a block diagram showing a wireless communication system, inaccordance with various aspects of the present disclosure.

FIG. 7 is a block diagram showing a wireless communication system, inaccordance with various aspects of the present disclosure.

FIG. 8 is a block diagram showing a wireless communication system, inaccordance with various aspects of the present disclosure.

FIG. 9 is a flow chart illustrating an example of a method forcommunication, in accordance with various aspects of the presentdisclosure.

FIG. 10 is a flow chart illustrating an example of a method forcommunication, in accordance with various aspects of the presentdisclosure.

FIG. 11 is a flow chart illustrating an example of a method forcommunication, in accordance with various aspects of the presentdisclosure.

FIG. 12 is a flow chart illustrating an example of a method forcommunication, in accordance with various aspects of the presentdisclosure.

FIG. 13 is a functional block diagram of an apparatus for communication,in accordance with various aspects of the present disclosure.

FIG. 14 is a functional block diagram of an apparatus for communication,in accordance with various aspects of the present disclosure.

FIG. 15 is a functional block diagram of an apparatus for communication,in accordance with various aspects of the present disclosure.

FIG. 16 is a functional block diagram of an apparatus for communication,in accordance with various aspects of the present disclosure.

DETAILED DESCRIPTION

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any aspect described herein as “exemplary”is not necessarily to be construed as preferred or advantageous overother aspects.

The following description provides examples, and is not limiting of thescope, applicability, or examples set forth in the claims. Changes maybe made in the function and arrangement of elements discussed withoutdeparting from the scope of the disclosure. Various examples may omit,substitute, or add various procedures or components as appropriate. Forinstance, the methods described may be performed in an order differentfrom that described, and various steps may be added, omitted, orcombined. Also, features described with respect to some examples may becombined in other examples.

In a communication system having UEs that may simultaneously supportboth 4G and 5G communication, it is possible that a UE may beoperatively coupled to a base station using 4G transmissions, but it mayalso be desirable for the UE to couple to the base station to support 5Gconnectivity. When coupling to a base station, a UE observessynchronization signals that allow the UE to establish proper timing andclocking of the transmission signals in order to establish acommunication channel with the base station. For example, in a UE havingdual connectivity capability including the ability to establish a 4Gcommunication channel and a 5G communication channel, a UE may becoupled to a base station using 4G connectivity, but may also wish tocouple to the base station using 5G connectivity. Therefore, it may beadvantageous to leverage at least some of the 4G connectivity and timingsynchronization parameters to allow the UE to efficiently establish 5Gconnectivity.

Exemplary embodiments of the disclosure are directed to synchronizationsignals used to establish wireless communication device connectivity andelements thereof, for example using an existing 4G synchronizationsignal to establish a clock and timing reference signal to allow theefficient establishment of 5G device connectivity.

FIG. 1 illustrates an example of a wireless communications system 100 inaccordance with various aspects of the disclosure. The wirelesscommunications system 100 includes base stations 105, UEs 115, and acore network 130. The core network 130 may provide user authentication,access authorization, tracking, Internet Protocol (IP) connectivity, andother access, routing, or mobility functions. The base stations 105interface with the core network 130 through a first set of backhaullinks 132 (e.g., S1, etc.) and may perform radio configuration andscheduling for communication with the UEs 115, or may operate under thecontrol of a base station controller (not shown). In various examples,the base stations 105 may communicate, either directly or indirectly(e.g., through core network 130), with each other over a second set ofbackhaul links 134 (e.g., X1, etc.), which may be wired or wirelesscommunication links.

The base stations 105 may wirelessly communicate with the UEs 115 viaone or more base station antennas. Each of the base station 105 sitesmay provide communication coverage for a respective geographic coveragearea 110. In some examples, base stations 105 may be referred to as abase transceiver station, a radio base station, an access point, a radiotransceiver, a gNodeB (gNB), a NodeB, eNodeB (eNB), Home NodeB, a HomeeNodeB, or some other suitable terminology. The geographic coverage area110 for a base station 105 may be divided into sectors making up only aportion of the coverage area (not shown). The wireless communicationssystem 100 may include base stations 105 of different types (e.g., macroand/or small cell base stations). There may be overlapping geographiccoverage areas 110 for different technologies.

In some examples, the wireless communications system 100 may be one ormore of an LTE/LTE-A network and a 5G network. In LTE/LTE-A networks,the term evolved Node B (eNB) may be generally used to describe the basestations 105, while the term UE may be generally used to describe theUEs 115. In contrast, in 5G or New Radio (NR) networks, base stations105 may be referred to as gNBs. The wireless communications system 100may be a Heterogeneous LTE/LTE-A network in which different types ofeNBs provide coverage for various geographical regions. For example,each eNB or base station 105 may provide communication coverage for amacro cell, a small cell, and/or other types of cell. The term “cell” isa 3GPP term that can be used to describe a base station, a carrier orcomponent carrier associated with a base station, or a coverage area(e.g., sector, etc.) of a carrier or base station, depending on context.In some examples, the wireless communications system 100 may be, or mayinclude a millimeter wave communication network.

A macro cell generally covers a relatively large geographic area (e.g.,several kilometers in radius) and may allow unrestricted access by UEswith service subscriptions with the network provider. A small cell is alower-powered base station, as compared with a macro cell, that mayoperate in the same or different (e.g., licensed, unlicensed, etc.)frequency bands as macro cells. Small cells may include pico cells,femto cells, and micro cells according to various examples. A pico cellmay cover a relatively smaller geographic area and may allowunrestricted access by UEs with service subscriptions with the networkprovider. A femto cell also may cover a relatively small geographic area(e.g., a home) and may provide restricted access by UEs having anassociation with the femto cell (e.g., UEs in a closed subscriber group(CSG), UEs for users in the home, and the like). An eNB for a macro cellmay be referred to as a macro eNB. An eNB for a small cell may bereferred to as a small cell eNB, a pico eNB, a femto eNB or a home eNB.An eNB may support one or multiple (e.g., two, three, four, and thelike) cells (e.g., component carriers).

The wireless communications system 100 may support synchronous orasynchronous operation. For synchronous operation, the base stations mayhave similar frame timing, and transmissions from different basestations may be approximately aligned in time. For asynchronousoperation, the base stations may have different frame timing, andtransmissions from different base stations may not be aligned in time.The techniques described herein may be used for either synchronous orasynchronous operations.

The communication networks that may accommodate some of the variousdisclosed examples may be packet-based networks that operate accordingto a layered protocol stack. In the user plane, communications at thebearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based.A Radio Link Control (RLC) layer may perform packet segmentation andreassembly to communicate over logical channels. A Medium Access Control(MAC) layer may perform priority handling and multiplexing of logicalchannels into transport channels. The MAC layer may also use Hybrid ARQ(HARQ) to provide retransmission at the MAC layer to improve linkefficiency. In the control plane, the Radio Resource Control (RRC)protocol layer may provide establishment, configuration, and maintenanceof an RRC connection between a UE 115 and the base stations 105 or corenetwork 130 supporting radio bearers for the user plane data. At thePhysical (PHY) layer, the transport channels may be mapped to Physicalchannels.

The UEs 115 are dispersed throughout the wireless communications system100, and each UE 115 may be stationary or mobile. A UE 115 may alsoinclude or be referred to by those skilled in the art as a mobilestation, a subscriber station, a mobile unit, a subscriber unit, awireless unit, a remote unit, a mobile device, a wireless device, awireless communications device, a remote device, a mobile subscriberstation, an access terminal, a mobile terminal, a wireless terminal, aremote terminal, a handset, a user agent, a mobile client, a client, orsome other suitable terminology. A UE 115 may be a cellular phone, apersonal digital assistant (PDA), a wireless modem, a wirelesscommunication device, a handheld device, a tablet computer, a laptopcomputer, a cordless phone, a wireless local loop (WLL) station, or thelike. A UE 115 may be able to communicate with various types of basestations and network equipment including macro eNBs/gNBs, small celleNBs/gNBs, relay base stations, and the like. A UE 115 may also be ableto communicate with other UEs either within or outside the same coveragearea of a base station via D2D communications.

The communication links 125 shown in wireless communications system 100may include uplink (UL) transmissions from a UE 115 to a base station105, and/or downlink (DL) transmissions, from a base station 105 to a UE115. The downlink transmissions may also be called forward linktransmissions while the uplink transmissions may also be called reverselink transmissions. Each communication link 125 may include one or morecarriers, where each carrier may be a signal made up of multiplesub-carriers (e.g., waveform signals of different frequencies) modulatedaccording to the various radio technologies described above. Eachmodulated signal may be sent on a different sub-carrier and may carrycontrol information (e.g., reference signals, control channels, etc.),overhead information, user data, etc. The communication links 125 maytransmit bidirectional communications using FDD (e.g., using pairedspectrum resources) or TDD operation (e.g., using unpaired spectrumresources). Frame structures for FDD (e.g., frame structure type 1) andTDD (e.g., frame structure type 2) may be defined. In an exemplaryembodiment, the communication links 125 may comprise one or more of anLTE communication link and a millimeter wave (mmW) communication link.

In some embodiments of the system 100, base stations 105 and/or UEs 115may include multiple antennas for employing antenna diversity schemes toimprove communication quality and reliability between base stations 105and UEs 115. Additionally or alternatively, base stations 105 and/or UEs115 may employ multiple-input, multiple-output (MIMO) techniques thatmay take advantage of multi-path environments to transmit multiplespatial layers carrying the same or different coded data.

Wireless communications system 100 may support directionalsynchronization signal for millimeter wave detection andsynchronization. For example, a millimeter wave base station 105 maytransmit a directional synchronization signal in a sweeping pattern toUEs 115 within its coverage area 110. The base station 105 may configurea narrowband signal of the synchronization signal to convey correlationinformation, such as location information (e.g., based on cell IDinformation included or conveyed in the narrowband signal), for awideband signal of the synchronization signal. Hereinafter, informationregarding the properties of the wideband signal may be referred to as“correlation information”. The base station 105 may link the widebandsignal to the location of the narrowband signal. In some examples, theidentification information of the base station 105 may be included orconveyed in the narrowband signal. The identification information mayconvey the location information, e.g., the UE 115 may perform a functionbased on the base station 105 identification number and/or access alookup table. The base station 105 may send the wideband signalcomponent of the synchronization signal according to the correlationinformation in the narrowband signal.

A UE 115 may receive the narrowband signal of the synchronization signalfor the millimeter wave communication network and determine thecorrelation information associated with the wideband signal from thenarrowband signal. For example, the UE 115 may identify the base station105 sending the narrowband signal, may determine the base station 105identity based on the frequency of the narrowband signal, etc., todetermine the correlation information. The UE 115 may use thecorrelation information to identify and receive the wideband signal. Insome examples, the UE 115 may determine timing information based on thenarrowband signal and/or the wideband signal components of thesynchronization signal, e.g., system timing, frame boundary/lengthtiming, etc.

In an aspect, the UE 115 is capable of communicating signals via the LTEnetwork and an mmW system (e.g., as a part of a 5G/NR system).Accordingly, the UE 115 may communicate with the base station 105 over aLTE link. Additionally, the UE 115 may communicate with a connectionpoint (CP), a base station (BS) (capable of mmW system communication),or a millimeter wave base station (mmW-BS) 135 over an mmW link.

In a further aspect, at least one of the base stations 105 may becapable of communicating signals via the LTE network and the mmW systemover one or more communication links 125. As such, a base station 135may be referred to as a LTE+mmW eNB or gNB or as a LTE+mmW CP/BS/mmW-BS.

In an exemplary embodiment, a UE may be operatively coupled to a basestation over an LTE/LTE-A communication channel, which may also bereferred to as a 4G communication channel. The UE may also be capable ofcommunication using what is referred to as 5G connectivity. In anexemplary embodiment, a 5G communication channel may use mmW accessfrequencies, on the order of 28 GHz (Gigahertz).

When developed by a low cost frequency source, such as a low costoscillator having, for example, a 20 part per million (ppm) accuracyover expected temperature variations, a frequency offset may occur atthe mmW access frequencies that may be on the order of ten times greaterthan the frequency offset developed by an oscillator operating at LTEfrequencies, on the order of 3 GHz.

In an exemplary embodiment, before establishing a mmW (5G) communicationlink, a UE may connect to a 4G (LTE) base station and may use at leastone 4G timing parameter or synchronization parameter, such as, forexample, a 4G frequency reference, to allow the 5G oscillator either tobe set accurately to a reference frequency (for example, the 4Gfrequency reference) or have a negligible frequency offset with respectto the frequency of the 4G frequency reference (i.e., have a negligiblefrequency offset compared to the frequency inaccuracy that the UE cantolerate without impacting communication quality). Alternatively, thefrequency offset of the 5G oscillator may be estimated and the initialfrequency established using the frequency of the 4G frequency referencebased on the 4G (LTE) connection with the base station. Thus, theeffective frequency offset of the 5G oscillator will be significantlyreduced from the initial exemplary 20 ppm and appear as an oscillator ina 4G communication device, i.e., an oscillator having a lower frequencyoffset, for example, a frequency offset on the order of an oscillatorhaving a 20 ppm accuracy operating at 3 GHz. Further, in an exemplaryembodiment, a modem in a 5G communication device can learn thetemperature dependency of the low cost frequency source used in the 5Goscillator over time and may therefore only rely on the 4Gsynchronization parameter during an initial learning phase.

Therefore, in a UE capable of both 4G and 5G connectivity, it would bedesirable to use one or more of the 4G synchronization parameters, suchas a timing reference signal, a synchronization signal, or another 4Gtiming reference signal, as a starting point for setting a 5G frequencyreference for establishing 5G connectivity. For example, variousembodiments described herein allow the use of a 4G clock signal, orother 4G timing or synchronization signal, to be used as a beginningreference point for establishing 5G synchronization between a UE and anetwork.

FIG. 2 is a block diagram 200 of a device 115-a for use in wirelesscommunication, in accordance with various aspects of the presentdisclosure. The device 115-a may be an example of one or more aspects ofa UE 115 described with reference to FIG. 1. The device 115-a mayinclude a receiver module 205, a synchronization module 210, and/or atransmitter module 215. The device 115-a may also be or include aprocessor (not shown). Each of these modules may be in communicationwith each other.

The components of the device 115-a may, individually or collectively, beimplemented using one or more application-specific integrated circuits(ASICs) adapted to perform some or all of the applicable functions inhardware. Alternatively, the functions may be performed by one or moreother processing units (or cores), on one or more integrated circuits.In other examples, other types of integrated circuits may be used (e.g.,Structured/Platform ASICs, Field Programmable Gate Arrays (FPGAs), andother Semi-Custom ICs), which may be programmed in any manner known inthe art. The functions of each module may also be implemented, in wholeor in part, with instructions embodied in a memory, formatted to beexecuted by one or more general or application-specific processors.

The receiver module 205 may receive information such as packets, userdata, and/or control information associated with various informationchannels (e.g., control channels, data channels, etc.). The receivermodule 205 may receive messages from a millimeter wave base station 105including information associated with synchronization signaling.Information may be passed on to the synchronization module 210, and toother components of the device 115-a.

The synchronization module 210 may manage synchronization functions forthe device 115-a. The synchronization module 210 may receive, via thereceiver module 205, a synchronization signal associated with 4Gconnectivity. For example, the synchronization module 210 may receive a1PPS (1 pulse per second) network reference synchronization signal for4G circuitry associated with the device 115-a. Alternatively, a clocksignal, a frequency reference signal, a frequency offset signal, orother clock and/or timing synchronization signal, that may be internalto the 4G circuitry on the device 115-a may be provided to 5G circuitryof the device 115-a to allow the device 115-a to efficiently achieve 5Gsynchronization using the 4G clock signal or other 4G synchronizationsignal.

The transmitter module 215 may transmit the one or more signals receivedfrom other components of the device 115-a. The transmitter module 215may transmit information such as packets, user data, and/or controlinformation to a serving cell. The transmitter module 215 may sendmessages to a millimeter wave base station 105 in conjunction withvarious synchronization signaling operations, e.g., random accessprocedures. In some examples, the transmitter module 215 may becollocated with the receiver module 205 in a transceiver module.

FIG. 3 is a block diagram 300 of a device 115-b for use in wirelesscommunication, in accordance with various examples. The device 115-b maybe an example of one or more aspects of a UE 115 described withreference to FIG. 1. It may also be an example of a device 115-adescribed with reference to FIG. 2. The device 115-b may include areceiver module 205-a, a synchronization module 210-a, and/or atransmitter module 215-a, which may be examples of the correspondingmodules of device 115-a. The device 115-b may also include a processor(not shown). Each of these components may be in communication with eachother. The synchronization module 210-a may include a timing referencemodule 310. The receiver module 205-a and the transmitter module 215-amay perform the functions of the receiver module 205 and the transmittermodule 215, of FIG. 2, respectively.

The components of the device 115-b may, individually or collectively, beimplemented using one or more application-specific integrated circuits(ASICs) adapted to perform some or all of the applicable functions inhardware. Alternatively, the functions may be performed by one or moreother processing units (or cores), on one or more integrated circuits.In other examples, other types of integrated circuits may be used (e.g.,Structured/Platform ASICs, Field Programmable Gate Arrays (FPGAs), andother Semi-Custom ICs), which may be programmed in any manner known inthe art. The functions of each module may also be implemented, in wholeor in part, with instructions embodied in a memory, formatted to beexecuted by one or more general or application-specific processors.

The synchronization signal detection module 305 may manage aspects ofsynchronization signal detection and management for the device 115-b.The synchronization signal detection module 305 may, in cooperation withthe receiver module 205-a and/or the transmitter module 215-a, receive asynchronization signal from a communication network or from a basestation 105 coupled to a communication network for millimeter wavecommunications.

In an exemplary embodiment, the synchronization signal detection module305 may detect a synchronization signal associated with a 4Gcommunication network, and may forward the 4G synchronization signal tothe timing reference module 310. In exemplary embodiments, thesynchronization signal associated with a 4G communication network maycomprise one or more of a 4G clock signal from which a 1PPSsynchronization signal may be generated and provided to 5G circuitry(not shown), a 4G clock signal that may be propagated from 4G circuitry(not shown) to 5G circuitry (not shown) via an internal interface (suchas a peripheral component interconnect-express (PCI-E)) interface, anoutput of a voltage controlled oscillator (VCO) associated with 4Gcircuitry (not shown) that may be provided to a VCO associated with 5Gcircuitry (not shown), or 4G circuitry analyzing a 5G clock signal andadjusting the 5G clock signal based on the analysis. Alternatively, thesynchronization signal associated with a 4G communication network may bea frequency reference signal, a frequency offset signal, or other clockand/or timing reference signal.

The timing reference module 310 may manage aspects of synchronizationreference timing for the device 115-b. For example, the timing referencemodule 310 may, in cooperation with the synchronization signal detectionmodule 305, determine one or more timing references for the device115-b. In an exemplary embodiment, the timing reference module 310 mayreceive a synchronization signal associated with a 4G communicationchannel and, using the 4G synchronization signal, establish a timingreference for 5G circuitry (not shown) in the device 115-b.

FIG. 4 is a block diagram 400 of a device 115-c for use in wirelesscommunication, in accordance with various examples. The device 115-c maybe an example of one or more aspects of a UE 115 described withreference to FIG. 1. It may also be an example of a device 115-adescribed with reference to FIG. 2 or an example of a device 115-bdescribed with reference to FIG. 3. The device 115-c may include firstcircuitry, which in this example, may be 4G circuitry 420 and mayinclude second circuitry, which in this example, may be 5G circuitry430. The 4G circuitry 420 may be coupled to an antenna 402 and the 5Gcircuitry 430 may be coupled to an antenna 412. Although shown as singleelements, the antenna 402 and the antenna 412 may comprise one or moreantenna elements, may comprise an array, or a phased array, of antennaelements, and may comprise one or more directional and/oromni-directional antenna elements.

In an exemplary embodiment, a base station 105 may include capability toestablish a 4G communication channel 403 with the 4G circuitry 420 andmay include capability to establish a 5G communication channel 404 withthe 5G circuitry 430. In an exemplary embodiment, a synchronizationsignal may be communicated from the base station 105 to the device 115-cvia the 4G circuitry 420, for example, as part of a network referencesignal. In an exemplary embodiment, the device 115-c may have anestablished 4G communication channel 403, but may not have anestablished 5G communication channel 404. In an exemplary embodiment, ifthe device 115-c has an established 4G communication channel 403 anddesires to establish a 5G communication channel 404, the 4G circuitry420 may be configured to interact with the 5G circuitry 430 toefficiently allow the 5G circuitry 430 to establish a faster acquisitionof the 5G communication channel 404 with the base station 105.

In an exemplary embodiment, the 4G circuitry 420 may provide a timingsynchronization parameter (e.g., a timing synchronization signal, afrequency reference signal, a frequency offset signal, or another timingand/or reference signal) to the 5G circuitry 430. In an exemplaryembodiment, the synchronization parameter may be a 1PPS timing referencesignal. In response, the 5G circuitry may process the 1PPS signal togenerate a timing reference signal (e.g., a control signal) that can beused to allow the 5G circuitry to establish a faster acquisition of the5G communication channel 404 with the base station 105.

In an exemplary embodiment, the 4G circuitry 420 and the 5G circuitry430 may communicate over an internal bus or connection, such as a PCI-Einternal interface, to allow a counter or register associated with the4G circuitry 420 to communicate with a counter or register associatedwith the 5G circuitry 430. In this way, the 5G circuitry 430 can receiveclock or timing information from the 4G circuitry 420, which allows the5G circuitry to establish a faster acquisition of the 5G communicationchannel 404 with the base station 105.

In an exemplary embodiment, the 5G circuitry 430 may receive clock ortiming information from a voltage controlled oscillator (VCO) associatedwith the 4G circuitry 420. The 5G circuitry 430 may be configured tocompare the clock or timing information from the VCO associated with the4G circuitry 420, and generate a control signal to adjust a VCOassociated with the 5G circuitry 430 to establish a faster acquisitionof the 5G communication channel 404 with the base station 105.

In an exemplary embodiment, the 4G circuitry 420 may receive clock ortiming information from a voltage controlled oscillator (VCO) associatedwith the 5G circuitry 430. The 4G circuitry 420 may be configured tocompare the clock or timing information from the VCO associated with the5G circuitry 430, and generate a control signal that the 5G circuitrymay use to generate a 5G control signal to adjust the VCO associatedwith the 5G circuitry 430 to establish a faster acquisition of the 5Gcommunication channel 404 with the base station 105.

FIG. 5 shows a system 500 for use in wireless communication, inaccordance with various examples. The system 500 may include a device115-d, which may be an example of the UE 115 of FIG. 1. The device 115-dmay also be an example of one or more aspects of devices 115 of FIGS. 2,3, and/or 4. The device 115-d may comprise 4G circuitry 520 and 5Gcircuitry 530. Some of the operational elements of the 4G circuitry 520and the 5G circuitry 530 may be omitted for ease of description, and areknown to those having ordinary skill in the art.

The device 115-d may generally include components for bi-directionalvoice and data communications including components for transmittingcommunications and components for receiving communications. The device115-d may include an antenna 502 coupled to the 4G circuitry 520, andmay include an antenna 512 coupled to the 5G circuitry 530. The antenna512 may comprise one or more antenna elements, may comprise an array, ora phased array, of antenna elements, and may comprise one or moredirectional and/or omni-directional antenna elements. The 4G circuitry520 may be configured to establish a 4G communication channel 503 with abase station (not shown) and the 5G circuitry 530 may be configured toestablish a 5G communication channel 504 with a base station (notshown).

The 4G circuitry 520 may comprise a baseband system 522 and a radiofrequency integrated circuit (RFIC) 523, the details of which are knownto those having ordinary skill in the art. The 4G circuitry 520 may beoperatively coupled to a voltage controlled oscillator 505 overconnection 552. A control signal may be developed by the 4G circuitry520 and provided to a control input of the VCO 505 over connection 506.The control signal on connection 506 may be used to adjust the outputfrequency, and other characteristics, of the VCO 505.

The 5G circuitry 530 may comprise a baseband system 532 and a radiofrequency integrated circuit (RFIC) 533. The baseband system 532 maycomprise a processor 536, a memory 537 (including software (SW) 539), asynchronization module 510 and a counter 544, which each maycommunicate, directly or indirectly, with each other (e.g., via one ormore buses 535). The RFIC 533 may comprise an intermediate frequency(IF) sub-system 526 and a transceiver module 528. In an exemplaryembodiment, the transceiver module 528 may be configured to communicateover millimeter wave (mmW) frequencies. The transceiver module 528 maycommunicate bi-directionally, via the antenna(s) 512 and/or one or morewired or wireless links, with one or more networks, as described above.For example, the transceiver module 528 may communicate bi-directionallywith base stations 105 (not shown), with other UEs 115, and/or withdevices 115 with reference to FIG. 1, 2, 3, or 4. The transceiver module528 may include a modem to modulate the packets and provide themodulated packets to the antenna(s) 512 for transmission, and todemodulate packets received from the antenna(s) 512. While the UE 115-dmay include a single antenna 512 for the 5G circuitry 530 and a singleantenna 502 for the 4G circuitry 520, the UE 115-d may have multipleantennas capable of concurrently transmitting and/or receiving multiplewireless transmissions via carrier aggregation techniques, for example.The transceiver module 528 may be capable of concurrently communicatingwith one or more base stations 105 via multiple component carriers.Moreover, the 4G circuitry 520 also comprises a transceiver module (notshown) that may also be capable of concurrently communicating with oneor more base stations 105 via multiple component carriers.

The 5G circuitry 530 may include a VCO 524 that may be operativelycoupled to the baseband system 532, the IF sub-system 526 and thetransceiver module 528 over connection 541. A control signal may bedeveloped by the 5G circuitry 530 and provided to a control input of theVCO 524 over connection 525. The control signal on connection 525 may beused to adjust the output frequency, and other characteristics, orparameters of the VCO 524.

The device 115-d may include a synchronization module 510, which mayperform the functions described above for the synchronization module 210of devices 115 of FIGS. 2, 3, and/or 4. In an exemplary embodiment, the5G circuitry 530 may be configured to receive a synchronization signalfrom the 4G circuitry 520 over connection 540. In an exemplaryembodiment, the synchronization signal on connection 540 may comprise a1PPS signal that may be developed by the 4G circuitry as part of theestablishment, or the ongoing operation, of a 4G communication channel503 between the 4G circuitry and the base station 105 (not shown).However, when it is desirable for the device 115-d to establish a 5Gcommunication channel 504 with the base station (not shown) in additionto the 4G communication channel 503, the time duration for establishingthe proper timing synchronization for a 5G communication channel 504 maybe reduced by using the timing synchronization signal (for example, the1PPS signal in this exemplary embodiment), provided by the 4G circuitry520.

In an exemplary embodiment, the 4G circuitry 520 receives a timingsynchronization signal from the network (not shown) and generates a 4G1PPS signal on connection 540. The 1PPS signal on connection 540 isprovided to the 5G circuitry 530. In an exemplary embodiment, a counter542 (CTR) in the 4G circuitry 520 counts the radio frames present in the1PPS signal based on the frequency of the VCO 505.

The baseband system 532 in the 5G circuitry 530 receives the 1PPS signaland also counts the radio frames present in one cycle of the 1PPSsignal, based on the frequency of the VCO 524, and stores the number ofradio frames in the counter 544 (CTR). The processor 536 in the basebandsystem 532 compares the number of radio frames in the counter 542 withthe number of radio frames in the counter 544 and uses the result tocalculate a frequency offset between the VCO 505 in the 4G circuitry 520and the VCO 524 in the 5G circuitry 530. The baseband system 532 thenuses the frequency offset to develop a control signal over connection525 to adjust the VCO 524 to synchronize the frequency of the VCO 524 tothe frequency of the VCO 505 using the 4G 1PPS signal. Alternatively, adigital numerically controlled oscillator (DNCO) may be incorporatedinto the baseband system 532 to generate the control signal.

The memory 537 may include random access memory (RAM) and read-onlymemory (ROM). The memory 537 may store computer-readable,computer-executable software/firmware code 539 containing instructionsthat, when executed, cause the processor 536 to perform variousfunctions described herein (e.g., perform synchronization operations,synchronize reference timing parameters, etc.). Alternatively, thecomputer-readable, computer-executable software/firmware code 539 maynot be directly executable by the processor 536 but cause a computer(e.g., when compiled and executed) to perform functions describedherein. The processor 536 may include an intelligent hardware device,e.g., a central processing unit (CPU), a microcontroller, anapplication-specific integrated circuit (ASIC), etc. In otherembodiments, the memory 537 may be on-board the processor 536.

FIG. 6 shows a system 600 for use in wireless communication, inaccordance with various examples. The system 600 may be similar to thesystem 500 and may include a device 115-e, which may be an example ofthe UE 115 of FIG. 1. The device 115-e may also be an example of one ormore aspects of devices 115 of FIGS. 2, 3, 4 and/or 5. The device 115-emay be similar to the device 115-d and elements in FIG. 6 that areidentical to elements in FIG. 5 are not described again in detail.

The device 115-e may include a synchronization module 610, which mayperform the functions described above for the synchronization module 210of devices 115 of FIGS. 2, 3, 4 and/or 5.

In an exemplary embodiment, the 4G circuitry 520 and the 5G circuitry530 may be coupled to a PCI-E bus 645. When it is desirable for thedevice 115-e to establish a 5G communication channel 504 with the basestation (not shown) in addition to the 4G communication channel 503, thetime duration for establishing the proper timing synchronization for a5G communication channel 504 may be reduced by using the output of the4G VCO 505 as a first timing synchronization parameter in this exemplaryembodiment, to set an initial frequency of the 5G VCO 524.

In an exemplary embodiment, the baseband system 522, via the counter 542in the 4G circuitry 520, counts the radio frames present in a definedperiod of time based on the frequency of the VCO 505, which issynchronized on the 4G network. The baseband system 522 stores thenumber of frames in the counter 542.

The baseband system 532 in the 5G circuitry 530 also counts the radioframes present in one defined period of time, based on the frequency ofthe VCO 524, and stores the number of radio frames in the counter 544.The processor 536 in the baseband system 532 compares the number ofradio frames in the counter 542 with the number of radio frames in thecounter 544 and uses the result to calculate a frequency offset betweenthe VCO 505 in the 4G circuitry 520 and the VCO 524 in the 5G circuitry530. The baseband system 532 then uses the frequency offset to develop acontrol signal over connection 525 to adjust the VCO 524 to synchronizethe VCO 524 to the 4G VCO 505. Alternatively, a digital numericallycontrolled oscillator (DNCO) may be incorporated into the basebandsystem 532 to generate the control signal.

FIG. 7 shows a system 700 for use in wireless communication, inaccordance with various examples. The system 700 may be similar to thesystem 500 and may include a device 115-f, which may be an example ofthe UE 115 of FIG. 1. The device 115-f may also be an example of one ormore aspects of devices 115 of FIGS. 2, 3, 4, 5 and/or 6. The device115-f may be similar to the device 115-d and elements in FIG. 7 that areidentical to elements in FIG. 5 are not described again in detail.

The device 115-f may include a synchronization module 710, which mayperform the functions described above for the synchronization module 210of devices 115 of FIGS. 2, 3, 4, 5 and/or 6.

In an exemplary embodiment, the output of the VCO 505 in the 4Gcircuitry 520 may be provided to the baseband system 532 over connection752 as a first timing synchronization parameter, in this exemplaryembodiment. The signal on connection 752 may be used to generate acontrol signal on connection 525 that can set the operating parametersof the VCO 524 in the 5G circuitry 530 to match the operating parametersof the VCO 505 in the 4G circuitry 520. For example, there can be aknown relation between the values of the VCO 505 in the 4G circuitry 520and the values of the VCO 524 in the 5G circuitry 530, so knowing thevalues of one could determine the values of the other. In this manner,the operating parameters of the VCO 505 in the 4G circuitry 520 areprovided to the 5G circuitry 530 as a robust starting point forsynchronizing the VCO 524 in the 5G circuitry 530 to enable the fasterestablishment of a 5G communication channel 504.

FIG. 8 shows a system 800 for use in wireless communication, inaccordance with various examples. The system 800 may be similar to thesystem 500 and may include a device 115-g, which may be an example ofthe UE 115 of FIG. 1. The device 115-g may also be an example of one ormore aspects of devices 115 of FIGS. 2, 3, 4, 5, 6 and/or 7. The device115-g may be similar to the device 115-d and elements in FIG. 8 that areidentical to elements in FIG. 5 are not described again in detail.

The device 115-g may include a synchronization module 810, which mayperform the functions described above for the synchronization module 210of devices 115 of FIGS. 2, 3, 4, 5, 6 and/or 7.

In an exemplary embodiment, the output of the VCO 524 in the 5Gcircuitry 530 may be provided to the 4G circuitry 520 over connection802 as a first timing synchronization parameter, in this exemplaryembodiment. In an exemplary embodiment, the baseband system 522, via thecounter 542 in the 4G circuitry 520, counts the frequency of the VCO505, and stores the frequency in the counter 542. The 4G circuitry 520compares the frequency of the VCO 524 against the frequency of the VCO505 and uses the result of the comparison to calculate a frequencyoffset between the VCO 505 in the 4G circuitry 520 and the VCO 524 inthe 5G circuitry 530. The 4G circuitry 520 then uses the frequencyoffset to develop a control signal, which is provided to the 5Gcircuitry 530 over connection 804. The 5G circuitry 530 then develops a5G control signal based on the control signal from the 4G circuitryprovided over connection 804 and provides the 5G control signal to theVCO 524 over connection 525 to adjust the VCO 524. Alternatively, adigital numerically controlled oscillator (DNCO) may be incorporatedinto the baseband system 532 to generate the 5G control signal.

FIG. 9 is a flow chart illustrating an example of a method 900 forcommunication, in accordance with various aspects of the presentdisclosure. The blocks in the method 900 can be performed in or out ofthe order shown, and in some embodiments, can be performed at least inpart in parallel.

In block 902 a 1PPS signal, which in this exemplary embodiment is afirst timing synchronization parameter, is propagated from firstcommunication circuitry, such as 4G communication circuitry 520, tosecond communication circuitry, such as 5G communication circuitry 530.

In block 904, the baseband system 532 (FIGS. 5-8) in the 5G circuitry530 counts a number of radio frames that may occur in the time period ofthe 1PPS signal based on the frequency of the VCO 524 and stores thenumber of radio frames in the counter 544.

In block 906, the baseband system 522 (FIGS. 5-8) in the 4G circuitry520 counts the radio frames present in the 1PPS signal based on thefrequency of the VCO 505 and stores the number of radio frames in thecounter 542.

In block 908, the baseband system 532 compares the number of radioframes in the counter 542 with the number of radio frames in the counter544 to determine a difference, and uses the result to calculate afrequency offset between the VCO 505 in the 4G circuitry 520 and the VCO524 in the 5G circuitry 530.

In block 910, the baseband system 532 then uses the frequency offset todevelop a control signal over connection 525 to adjust the VCO 524.Consequently, the baseband system 532 can synchronize the VCO 524 to the4G 1PPS signal.

FIG. 10 is a flow chart illustrating an example of a method 1000 forcommunication, in accordance with various aspects of the presentdisclosure. The blocks in the method 1000 can be performed in or out ofthe order shown, and in some embodiments, can be performed at least inpart in parallel.

In block 1002, the baseband system 522, via the counter 542 in the 4Gcircuitry 520, counts the radio frames present in a defined period oftime based on the frequency of the VCO 505, and stores the number offrames.

In block 1004, the baseband system 532, via the counter 544 in the 5Gcircuitry 530, counts the radio frames present in one defined period oftime, based on the frequency of the VCO 524 and stores the number ofradio frames.

In block 1006, a communication bus, such as a PCI-E bus 645 (FIG. 6),allows the 4G circuitry 520 and the 5G circuitry 530 to communicate, andallows the information in the counters 542 and 544 to be accessible toboth the 4G circuitry 520 and the 5G circuitry 530.

In block 1008, the baseband system 532 compares the number of radioframes in the counter 542 with the number of radio frames in the counter544 to determine a difference, and uses the result to calculate afrequency offset between the VCO 505 in the 4G circuitry 520 and the VCO524 in the 5G circuitry 530.

In block 1010, the baseband system 532 then uses the frequency offset todevelop a control signal over connection 525 to adjust the VCO 524 tosynchronize the 5G VCO 524 to the 4G VCO 505.

FIG. 11 is a flow chart illustrating an example of a method 1100 forcommunication, in accordance with various aspects of the presentdisclosure. The blocks in the method 1100 can be performed in or out ofthe order shown, and in some embodiments, can be performed at least inpart in parallel.

In block 1102, the output of the 4G VCO 505 is provided to the basebandsystem 532 in the 5G circuitry 530.

In block 1104, the operating parameters of the VCO 524 in the 5Gcircuitry 530 can be set to match the operating parameters of the VCO505 in the 4G circuitry 520. In this manner, the operating parameters,such as the operating frequency, of the VCO 505 in the 4G circuitry 520are provided to the 5G circuitry 530 as a robust starting point, orbasis, for synchronizing and setting the frequency of the VCO 524 in the5G circuitry 530 to enable the establishment of a 5G communicationchannel 504.

FIG. 12 is a flow chart illustrating an example of a method 1200 forcommunication, in accordance with various aspects of the presentdisclosure. The blocks in the method 1200 can be performed in or out ofthe order shown, and in some embodiments, can be performed at least inpart in parallel.

In block 1202, the output of the VCO 524 in the 5G circuitry 530 may beprovided to the 4G circuitry 520. In an exemplary embodiment, the outputof the VCO 524 in the 5G circuitry 530 may be considered a “freerunning” clock.

In block 1204, the baseband system 522, via the counter 542 in the 4Gcircuitry 520, counts the frequency of the VCO 505, and stores thefrequency in the counter 542. The 4G circuitry 520 compares thefrequency of the VCO 524 against the frequency of the VCO 505 todetermine a difference and uses the result of the comparison tocalculate a frequency offset between the VCO 505 in the 4G circuitry 520and the VCO 524 in the 5G circuitry 530.

In block 1206, the 4G circuitry 520 then uses the frequency offset todevelop a control signal, which is provided to the 5G circuitry 530 overconnection 804. In block 1208, the 5G circuitry 530 then develops a 5Gcontrol signal based on the control signal from the 4G circuitryprovided over connection 804 and provides the 5G control signal to theVCO 524 over connection 525 to adjust the VCO 524.

FIG. 13 is a functional block diagram of an apparatus 1300 forcommunication, in accordance with various aspects of the presentdisclosure. The apparatus 1300 comprises means 1302 for propagating a1PPS signal, which in this exemplary embodiment is a first timingsynchronization parameter, from first communication circuitry, such as4G communication circuitry 520, to second communication circuitry, suchas 5G communication circuitry 530. In certain embodiments, the means1302 for propagating a 1PPS signal from first communication circuitry tosecond communication circuitry can be configured to perform one or moreof the function described in operation block 902 of method 900 (FIG. 9).In an exemplary embodiment, the means 1302 for propagating a 1PPS signalfrom first communication circuitry to second communication circuitry maycomprise propagating a 1PPS signal from the 4G communication circuitry520 to the 5G communication circuitry 530.

The apparatus 1300 further comprises means 1304 for counting a number ofradio frames that may occur in the time period of the 1PPS signal andstoring the number of radio frames. In certain embodiments, the means1304 for counting a number of radio frames that may occur in the timeperiod of the 1PPS signal and storing the number of radio frames can beconfigured to perform one or more of the function described in operationblock 904 of method 900 (FIG. 9). In an exemplary embodiment, the means1304 for counting a number of radio frames that may occur in the timeperiod of the 1PPS signal and storing the number of radio frames maycomprise the baseband system 532 in the 5G circuitry 530 counting anumber of radio frames that may occur in the time period of the 1PPSsignal based on the frequency of the VCO 524, and storing the number ofradio frames in the counter 544.

The apparatus 1300 further comprises means 1306 for counting a number ofradio frames that may occur in the time period of the 1PPS signal andstoring the number of radio frames. In certain embodiments, the means1306 for counting a number of radio frames that may occur in the timeperiod of the 1PPS signal and storing the number of radio frames can beconfigured to perform one or more of the function described in operationblock 906 of method 900 (FIG. 9). In an exemplary embodiment, the means1306 for counting a number of radio frames that may occur in the timeperiod of the 1PPS signal and storing the number of radio frames maycomprise the baseband system 522, via the counter 542 in the 4Gcircuitry 520, counting the radio frames present in the 1PPS signalbased on the frequency of the VCO 505 and storing the number of radioframes in the counter 542.

The apparatus 1300 further comprises means 1308 for comparing the numberof radio frames in the counter 542 with the number of radio frames inthe counter 544 to determine a difference, and calculating a frequencyoffset. In certain embodiments, the means 1308 for comparing the numberof radio frames in the counter 542 with the number of radio frames inthe counter 544 to determine a difference, and calculating a frequencyoffset can be configured to perform one or more of the functiondescribed in operation block 908 of method 900 (FIG. 9). In an exemplaryembodiment, the means 1308 for comparing the number of radio frames inthe counter 542 with the number of radio frames in the counter 544 todetermine a difference, and calculating a frequency offset may comprisecomparing the number of radio frames in the counter 542 with the numberof radio frames in the counter 544, and using the result to calculate afrequency offset between the VCO 505 in the 4G circuitry 520 and the VCO524 in the 5G circuitry 530.

The apparatus 1300 further comprises means 1310 for using the frequencyoffset to develop a control signal to synchronize the 5G VCO to the 4G1PPS signal. In certain embodiments, the means 1310 for using thefrequency offset to develop a control signal to synchronize the 5G VCOto the 4G 1PPS signal can be configured to perform one or more of thefunction described in operation block 910 of method 900 (FIG. 9). In anexemplary embodiment, the means 1310 for using the frequency offset todevelop a control signal to synchronize the 5G VCO to the 4G 1PPS signalmay comprise the baseband system 532 using the frequency offset todevelop a control signal over connection 525 to adjust the VCO 524 tosynchronize the VCO 524 to the 4G 1PPS signal.

FIG. 14 is a functional block diagram of an apparatus 1400 forcommunication, in accordance with various aspects of the presentdisclosure. The apparatus 1400 comprises means 1402 for counting anumber of radio frames based on a 4G VCO and storing the number of radioframes. In certain embodiments, the means 1402 for counting a number ofradio frames based on a 4G VCO and storing the number of radio framescan be configured to perform one or more of the function described inoperation block 1002 of method 1000 (FIG. 10). In an exemplaryembodiment, the means 1402 for counting a number of radio frames basedon a 4G VCO and storing the number of radio frames may comprise thebaseband system 522, via the counter 542 in the 4G circuitry 520,counting the radio frames present in a defined period of time based onthe frequency of the VCO 505, and storing the number of frames in thecounter 542.

The apparatus 1400 further comprises means 1404 for counting a number ofradio frames based on a 5G VCO and storing the number of radio frames.In certain embodiments, the means 1404 for counting a number of radioframes based on a 5G VCO and storing the number of radio frames can beconfigured to perform one or more of the function described in operationblock 1004 of method 1000 (FIG. 10). In an exemplary embodiment, themeans 1404 for counting a number of radio frames based on a 5G VCO andstoring the number of radio frames may comprise the baseband system 532,via the counter 544 in the 5G circuitry 530, counting the radio framespresent in a defined period of time based on the frequency of the VCO524, and storing the number of frames.

The apparatus 1400 further comprises means 1406 for the 5G circuitryaccessing the 4G radio frame counts over a system bus. In certainembodiments, the means 1406 for the 5G circuitry accessing the 4G radioframe counts over a system bus can be configured to perform one or moreof the function described in operation block 1006 of method 1000 (FIG.10). In an exemplary embodiment, the means 1406 for the 5G circuitryaccessing the 4G radio frame counts over a system bus may comprise the4G circuitry 520 and the 5G circuitry 530 communicating over acommunication bus, such as a PCI-E bus 645, and allowing the informationin the counters 542 and 544 to be accessible to both the 4G circuitry520 and the 5G circuitry 530.

The apparatus 1400 further comprises means 1408 for comparing the numberof radio frames in the counter 542 with the number of radio frames inthe counter 544 to determine a difference, and calculating a frequencyoffset. In certain embodiments, the means 1408 for comparing the numberof radio frames in the counter 542 with the number of radio frames inthe counter 544 to determine a difference, and calculating a frequencyoffset can be configured to perform one or more of the functiondescribed in operation block 1008 of method 1000 (FIG. 10). In anexemplary embodiment, the means 1408 for comparing the number of radioframes in the counter 542 with the number of radio frames in the counter544 to determine a difference, and calculating a frequency offset maycomprise comparing the number of radio frames in the counter 542 withthe number of radio frames in the counter 544, and using the result tocalculate a frequency offset between the VCO 505 in the 4G circuitry 520and the VCO 524 in the 5G circuitry 530.

The apparatus 1400 further comprises means 1410 for using the frequencyoffset to develop a control signal to synchronize the 5G VCO to the 4GVCO. In certain embodiments, the means 1410 for using the frequencyoffset to develop a control signal to synchronize the 5G VCO to the 4GVCO can be configured to perform one or more of the function describedin operation block 1010 of method 1000 (FIG. 10). In an exemplaryembodiment, the means 1410 for using the frequency offset to develop acontrol signal to synchronize the 5G VCO to the 4G VCO may comprise thebaseband system 532 using the frequency offset to develop a controlsignal over connection 525 to adjust the VCO 524 to synchronize the VCO524 to the 4G VCO.

FIG. 15 is a functional block diagram of an apparatus 1500 forcommunication, in accordance with various aspects of the presentdisclosure. The apparatus 1500 comprises means 1502 for providing theoutput of the 4G VCO to the baseband system in the 5G circuitry. Incertain embodiments, the means 1502 for providing the output of the 4GVCO to the baseband system in the 5G circuitry can be configured toperform one or more of the function described in operation block 1102 ofmethod 1100 (FIG. 11). In an exemplary embodiment, the means 1502 forproviding the output of the 4G VCO to the baseband system in the 5Gcircuitry may comprise providing the output of the 4G VCO 505 to thebaseband system 532 in the 5G circuitry 530.

The apparatus 1500 further comprises means 1504 for using the 4G VCOoutput as a starting point to set one or more parameters of the 5G VCO.In certain embodiments, the means 1504 for using the 4G VCO output as astarting point to set one or more parameters of the 5G VCO can beconfigured to perform one or more of the function described in operationblock 1104 of method 1100 (FIG. 11). In an exemplary embodiment, themeans 1504 for using the 4G VCO output as a starting point, to set oneor more parameters of the 5G VCO may comprise setting one or moreoperating parameters, such as frequency, of the VCO 524 in the 5Gcircuitry 530 to match one or more operating parameters, such asfrequency, of the VCO 505 in the 4G circuitry 520.

FIG. 16 is a functional block diagram of an apparatus 1600 forcommunication, in accordance with various aspects of the presentdisclosure. The apparatus 1600 comprises means 1602 for providing theoutput of the VCO in the 5G circuitry to the 4G circuitry. In certainembodiments, the means 1602 for providing the output of the VCO in the5G circuitry to the 4G circuitry can be configured to perform one ormore of the function described in operation block 1202 of method 1200(FIG. 12). In an exemplary embodiment, the means 1602 for providing theoutput of the VCO in the 5G circuitry to the 4G circuitry may compriseproviding the output of the 4G VCO 505 to the baseband system 532 in the5G circuitry 530. In an exemplary embodiment, the output of the VCO 524in the 5G circuitry 530 may be considered a “free running” clock.

The apparatus 1600 further comprises means 1604 for counting and storingthe 4G VCO output, comparing the 4G VCO output to the 5G VCO todetermine a difference, and calculating a frequency offset between theVCO in the 4G circuitry and the VCO in the 5G circuitry. In certainembodiments, the means 1604 for counting and storing the 4G VCO output,comparing the 4G VCO output to the 5G VCO to determine a difference, andcalculating a frequency offset between the VCO in the 4G circuitry andthe VCO in the 5G circuitry can be configured to perform one or more ofthe function described in operation block 1204 of method 1200 (FIG. 12).In an exemplary embodiment, the means 1604 for counting and storing the4G VCO output, comparing the 4G VCO output to the 5G VCO to determine adifference, and calculating a frequency offset between the VCO in the 4Gcircuitry and the VCO in the 5G circuitry may comprise the basebandsystem 522, via the counter 542 in the 4G circuitry 520, counting thefrequency of the VCO 505, and storing the frequency in the counter 542.The 4G circuitry 520 compares the frequency of the VCO 524 against thefrequency of the VCO 505 and uses the result of the comparison tocalculate a frequency offset between the VCO 505 in the 4G circuitry 520and the VCO 524 in the 5G circuitry 530.

The apparatus 1600 further comprises means 1606 for using the frequencyoffset to develop a control signal that is provided to the 5G VCO. Incertain embodiments, the means 1606 for using the frequency offset todevelop a control signal that is provided to the 5G VCO can beconfigured to perform one or more of the function described in operationblock 1206 of method 1200 (FIG. 12). In an exemplary embodiment, themeans 1606 for using the frequency offset to develop a control signalthat is provided to the 5G VCO to the 4G VCO may comprise the 4Gcircuitry 520 using the frequency offset to develop a control signal,which is provided to the 5G circuitry 530 over connection 804.

The apparatus 1600 further comprises means 1608 for developing a controlsignal based on the 4G control signal to adjust the 5G VCO. In certainembodiments, the means 1608 for developing a control signal based on the4G control signal to adjust the 5G VCO can be configured to perform oneor more of the function described in operation block 1208 of method 1200(FIG. 12). In an exemplary embodiment, the means 1608 for developing acontrol signal based on the 4G control signal to adjust the 5G VCO maycomprise the 5G circuitry 530 developing a control signal based on thecontrol signal from the 4G circuitry provided over connection 804 andproviding it to the VCO 524 over connection 525 to adjust the VCO 524.

Techniques described herein may be used for various wirelesscommunications systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, andother systems. The terms “system” and “network” are often usedinterchangeably. A CDMA system may implement a radio technology such asCDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases 0 and Aare commonly referred to as CDMA2000 1x, 1x, etc. IS-856 (TIA-856) iscommonly referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD),etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. ATDMA system may implement a radio technology such as Global System forMobile Communications (GSM). An OFDMA system may implement a radiotechnology such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA),IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM™, etc.UTRA and E-UTRA are part of Universal Mobile Telecommunication System(UMTS). 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are newreleases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, andGSM are described in documents from an organization named “3rdGeneration Partnership Project” (3GPP). CDMA2000 and UMB are describedin documents from an organization named “3rd Generation PartnershipProject 2” (3GPP2). The techniques described herein may be used for thesystems and radio technologies mentioned above as well as other systemsand radio technologies, including cellular (e.g., LTE) communicationsover an unlicensed and/or shared bandwidth. The description above,however, describes an LTE/LTE-A system for purposes of example, and LTEterminology is used in much of the description above, although thetechniques are applicable beyond LTE/LTE-A applications.

The detailed description set forth above in connection with the appendeddrawings describes examples and does not represent the only examplesthat may be implemented or that are within the scope of the claims. Theterms “example” and “exemplary,” when used in this description, mean“serving as an example, instance, or illustration,” and not “preferred”or “advantageous over other examples.” The detailed description includesspecific details for the purpose of providing an understanding of thedescribed techniques. These techniques, however, may be practicedwithout these specific details. In some instances, well-known structuresand apparatuses are shown in block diagram form in order to avoidobscuring the concepts of the described examples.

Information and signals may be represented using any of a variety ofdifferent technologies and techniques. For example, data, instructions,commands, information, signals, bits, symbols, and chips that may bereferenced throughout the above description may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, or any combination thereof.

The various illustrative blocks and components described in connectionwith the disclosure herein may be implemented or performed with ageneral-purpose processor, a digital signal processor (DSP), an ASIC, anFPGA or other programmable logic device, discrete gate or transistorlogic, discrete hardware components, or any combination thereof designedto perform the functions described herein. A general-purpose processormay be a microprocessor, but in the alternative, the processor may beany conventional processor, controller, microcontroller, or statemachine. A processor may also be implemented as a combination ofcomputing devices, e.g., a combination of a DSP and a microprocessor,multiple microprocessors, one or more microprocessors in conjunctionwith a DSP core, or any other such configuration.

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on acomputer-readable medium. Other examples and implementations are withinthe scope and spirit of the disclosure and appended claims. For example,due to the nature of software, functions described above can beimplemented using software executed by a processor, hardware, firmware,hardwiring, or combinations of any of these. Features implementingfunctions may also be physically located at various positions, includingbeing distributed such that portions of functions are implemented atdifferent physical locations. As used herein, including in the claims,the term “and/or,” when used in a list of two or more items, means thatany one of the listed items can be employed by itself, or anycombination of two or more of the listed items can be employed. Forexample, if a composition is described as containing components A, B,and/or C, the composition can contain A alone; B alone; C alone; A and Bin combination; A and C in combination; B and C in combination; or A, B,and C in combination. Also, as used herein, including in the claims,“or” as used in a list of items (for example, a list of items prefacedby a phrase such as “at least one of” or “one or more of”) indicates adisjunctive list such that, for example, a list of “at least one of A,B, or C” means A or B or C or AB or AC or BC or ABC (i.e., A and B andC).

Computer-readable media includes both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. A storage medium may be anyavailable medium that can be accessed by a general purpose or specialpurpose computer. By way of example, and not limitation,computer-readable media can comprise RAM, ROM, EEPROM, flash memory,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium that can be used to carryor store desired program code means in the form of instructions or datastructures and that can be accessed by a general-purpose orspecial-purpose computer, or a general-purpose or special-purposeprocessor. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, include compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and Blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above are also includedwithin the scope of computer-readable media.

As used in this description, the terms “component,” “database,”“module,” “system,” and the like are intended to refer to acomputer-related entity, either hardware, firmware, a combination ofhardware and software, software, or software in execution. For example,a component may be, but is not limited to being, a process running on aprocessor, a processor, an object, an executable, a thread of execution,a program, and/or a computer. By way of illustration, both anapplication running on a computing device and the computing device maybe a component. One or more components may reside within a processand/or thread of execution, and a component may be localized on onecomputer and/or distributed between two or more computers. In addition,these components may execute from various computer readable media havingvarious data structures stored thereon. The components may communicateby way of local and/or remote processes such as in accordance with asignal having one or more data packets (e.g., data from one componentinteracting with another component in a local system, distributedsystem, and/or across a network such as the Internet with other systemsby way of the signal).

The previous description of the disclosure is provided to enable aperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other variations without departing from the scope of thedisclosure. Thus, the disclosure is not to be limited to the examplesand designs described herein but is to be accorded the broadest scopeconsistent with the principles and novel features disclosed herein.

What is claimed is:
 1. A method for clock synchronization in acommunication system having first circuitry coupled to a firstcommunication channel and second circuitry, comprising: generating afirst timing synchronization parameter; and synchronizing the secondcircuitry to a second communication channel using the first timingsynchronization parameter.
 2. The method of claim 1, wherein the firsttiming synchronization parameter comprises a 1 pulse per second (PPS)signal generated by the first circuitry and the method furthercomprises: counting a first number of radio frames that occur within a1PPS time period; counting a second number of radio frames that occurwithin the 1PPS time period; comparing the first number of radio frameswith the second number of radio frames; calculating a frequency offsetbased on a difference between the first number of radio frames and thesecond number of radio frames; developing a control signal based on thefrequency offset; and using the control signal to adjust a timingreference associated with the second communication channel.
 3. Themethod of claim 1, wherein the first timing synchronization parametercomprises a first timing reference associated with the firstcommunication channel, and the method further comprises: counting afirst number of radio frames associated with the first timing reference;counting a second number of radio frames associated with a second timingreference associated with the second communication channel; comparingthe first number of radio frames with the second number of radio frames;calculating a frequency offset based on a difference between the firstnumber of radio frames and the second number of radio frames; developinga control signal based on the frequency offset; and using the controlsignal to adjust the second timing reference associated with the secondcommunication channel.
 4. The method of claim 1, wherein the firsttiming synchronization parameter comprises a first timing referenceassociated with the first communication channel, and the method furthercomprises: providing the first timing reference associated with thefirst communication channel to the second circuitry as a basis forestablishing a second timing reference associated with the secondcircuitry.
 5. The method of claim 1, wherein the first circuitrycomprises 4G communication circuitry and the second circuitry comprises5G communication circuitry.
 6. The method of claim 2, wherein the 1PPSsignal is generated by the first circuitry based on a network referencesignal.
 7. The method of claim 3, wherein the comparing furthercomprises accessing the first number of radio frames and the secondnumber of radio frames over a communication bus.
 8. An apparatus forclock synchronization in a communication system, comprising: firstcircuitry coupled to a first communication channel; second circuitry;and a first timing synchronization parameter configured to allow thesecond circuitry to establish communication with a second communicationchannel
 9. The apparatus of claim 8, wherein the first timingsynchronization parameter comprises a 1 pulse per second (PPS) signalgenerated by the first circuitry and the apparatus further comprises: afirst counter configured to count a first number of radio frames thatoccur within a 1PPS time period; a second counter configured to count asecond number of radio frames that occur within the 1PPS time period; abaseband system configured to compare the first number of radio frameswith the second number of radio frames; the baseband system configuredto calculate a frequency offset based on a difference between the firstnumber of radio frames and the second number of radio frames; and thebaseband system configured to develop a control signal based on thefrequency offset, wherein the control signal adjusts a timing referenceassociated with the second communication channel.
 10. The apparatus ofclaim 8, wherein the first timing synchronization parameter comprises afirst timing reference associated with the first communication channel,and the apparatus further comprises: a first counter configured to counta first number of radio frames associated with the first timingreference; a second counter configured to count a second number of radioframes associated with a second timing reference associated with thesecond communication channel; a baseband system configured to comparethe first number of radio frames with the second number of radio frames;the baseband system configured to calculate a frequency offset based ona difference between the first number of radio frames and the secondnumber of radio frames; and the baseband system configured to develop acontrol signal based on the frequency offset, wherein the control signaladjusts a timing reference associated with the second communicationchannel.
 11. The apparatus of claim 8, wherein the first timingsynchronization parameter comprises a first timing reference associatedwith the first communication channel, and the apparatus furthercomprises: a baseband system configured to provide the first timingreference associated with the first communication channel to the secondcircuitry as a basis for establishing a second timing referenceassociated with the second circuitry.
 12. The apparatus of claim 8,wherein the first circuitry comprises 4G communication circuitry and thesecond circuitry comprises 5G communication circuitry.
 13. The apparatusof claim 9, wherein the 1PPS signal comprises a network referencesignal.
 14. The apparatus of claim 10, further comprising acommunication bus configured to allow the baseband system to access thefirst number of radio frames and the second number of radio frames. 15.A device, comprising: means for coupling first circuitry to a firstcommunication channel; means for generating a first timingsynchronization parameter; and means for synchronizing second circuitryto a second communication channel using the first timing synchronizationparameter.
 16. The device of claim 15, wherein the first timingsynchronization parameter comprises a 1 pulse per second (PPS) signalgenerated by the first circuitry and the device further comprises: meansfor counting a first number of radio frames that occur within a 1PPStime period; means for counting a second number of radio frames thatoccur within the 1PPS time period; means for comparing the first numberof radio frames with the second number of radio frames; means forcalculating a frequency offset based on a difference between a firstnumber of radio frames and the second number of radio frames; means fordeveloping a control signal based on the frequency offset; and means forusing the control signal to adjust a timing reference associated withthe second communication channel.
 17. The device of claim 15, whereinthe first timing synchronization parameter comprises a first timingreference associated with the first communication channel, the devicefurther comprising: means for counting a first number of radio framesassociated with the first timing reference; means for counting a secondnumber of radio frames associated with a second timing referenceassociated with the second communication channel; means for comparingthe first number of radio frames with the second number of radio frames;means for calculating a frequency offset based on a difference betweenthe first number of radio frames and the second number of radio frames;and means for developing a control signal based on the frequency offset;and means for using the control signal to adjust the second timingreference associated with the second communication channel.
 18. Thedevice of claim 15, wherein the first timing synchronization parametercomprises a first timing reference associated with the firstcommunication channel, and the device further comprises: means forproviding the first timing reference associated with the firstcommunication channel to the second circuitry as a basis forestablishing a second timing reference associated with the secondcircuitry.
 19. The device of claim 15, wherein the first circuitrycomprises 4G communication circuitry and the second circuitry comprises5G communication circuitry.
 20. The device of claim 16, wherein the 1PPSsignal is generated by the first circuitry based on a network referencesignal.
 21. The device of claim 17, wherein the means for comparingfurther comprises means for accessing the first number of radio framesand the second number of radio frames.
 22. A non-transitorycomputer-readable medium storing computer executable code for clocksynchronization in a communication system having first circuitry coupledto a first communication channel and second circuitry, the codeexecutable by a processor to: generate a first timing synchronizationparameter; and synchronize the second circuitry to a secondcommunication channel using the first timing synchronization parameter.23. The non-transitory computer-readable medium of claim 22, wherein thefirst timing synchronization parameter comprises a 1 pulse per second(PPS) signal generated by the first circuitry and the code is executableby a processor to: count a first number of radio frames that occurwithin a 1PPS time period; count a second number of radio frames thatoccur within the 1PPS time period; compare the first number of radioframes with the second number of radio frames; calculate a frequencyoffset based on a difference between the first number of radio framesand the second number of radio frames; develop a control signal based onthe frequency offset; and use the control signal to adjust a timingreference associated with the second communication channel.
 24. Thenon-transitory computer-readable medium of claim 22, wherein the firsttiming synchronization parameter comprises a first timing referenceassociated with the first communication channel, and the code isexecutable by a processor to: count a first number of radio framesassociated with the first timing reference; count a second number ofradio frames associated with a second timing reference associated withthe second communication channel; compare the first number of radioframes with the second number of radio frames; calculate a frequencyoffset based on a difference between the first number of radio framesand the second number of radio frames; develop a control signal based onthe frequency offset; and use the control signal to adjust the secondtiming reference associated with the second communication channel. 25.The non-transitory computer-readable medium of claim 22, wherein thefirst timing synchronization parameter comprises a first timingreference associated with the first communication channel, and the codeis executable by a processor to: provide the first timing referenceassociated with the first communication channel to the second circuitryas a basis for establishing a second timing reference associated withthe second circuitry.
 26. The non-transitory computer-readable medium ofclaim 22, wherein the first circuitry comprises 4G communicationcircuitry and the second circuitry comprises 5G communication circuitry.